Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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Backrround of the Invention
This invention relates to a method and apparatus
for traversing a strand or strands to form a restrained
cross-laid web. More particularly, it relates to a method
adaptable to forming restrained webs of a wide variety of
strand laydown patterns, and to apparatus upon which the
method can be carried out at high speed.
A "restrained web" is one in which the strands
which comprise the ~eb, aft~r being cross-laid in a given
configuration, are held in that configuration by pins or
other restraining elements until a desired operation is
carried out upon the web. Additional tension may be applied
to the restrained web by increasing the distance of the pins
across the web after it is laid.
Many types of machines ha~e been developed for
withdrawing a strand from a package and traversing it
across a moving conveyor to form a web useful for rein-
forcing paper or other sheet materials, or for forming
scr~m or other ~abrics. The cross-laid web is fre~uently
combined with a warp sheet of strands, and the two sheets
may be bonded together with adhesives or othe~lise. How-
ever~ most of the prior art apparatus can be operated only
at relatively low speed. Many of these machines are
restricted to laydown of a single ~trand, and others are
incapable of forming a restrained web. Most of the prlor
art machines are restricted to a particular laydown
pattern, e.g., a diagonal patte m , which can be varied
only to a minor extent such as by changing the spacing
of the strands. In partlculnr, the achievement of a truly
orthogonal laydowll has been a problem ln the prlor art.
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This ls lmportant, since for many products it is desired
to have re~nforcin~ strands across the width of the
product at right angles to the long or machine direction
of the product.
Though the term "strand" will be used through-
out the specification, this term is meant to include
materials such as yarn~ threads, cords, filaments and the
like. Such strands may be of either natural or synthetic
material. ^
Su~nary of the Invention
,
According to this invention a new method and
apparatus have been developed for cross laying or tra-
versing strands at 90 degrees or other angles to the
machine direction at relatively high speed. The apparatus
is one for traversing a strand between two spaced rows of
; strand-restraining elements moving together in the same
direction at the same speed in the same plane to form a
web. The apparatus lncludes a strand supply source, a
guide located out of the plane of the rows of strand-
restraining elements but ~etween the rows for receiving
the strand from the supply source, and at least one pair
of rotatable strand-engaging members associated with each
row o~ strand-restraining elements for slidably engaging
the strand between the guide and the plane of the rows
and traversing the strand toward one and then the other
row while forming a loop in the strand during each tra-
verse. The loop is brought into a plane substantially
parallel with-the plane of the rows and extended beyond
the rows and ls then disengased from the strand-engaging
members and deposlted about ~t least one of the strand-
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restraining elements,
The method involves not only forming a loop in
the strand in the plane of traverse but turning the loop
out of the plane Or tra~erse into a plane su~stantially
parallel wit~ the plane of the strand-restraining elements
and then depositing the loop thus oriented onto at least
. one of the strand-restraining elements to form a restrained
cross-laid web.
Brief Description of the Illustrated Efflbodiments
_
Fig. l is a front elevation of the apparatus
for traversing strahds according to the present invention,
Fig. 2 is a top view of the apparatus shown in.
Fig. l.
Fig. 3 is a partially sectioned vlew of the
apparatus shown in Fig. l taken along 3-3.
Fig. 4 is a perspective view showing the rela-
tionship of hooks and spreaders on the rotating disks
for traversing two strands onto the pin conveyor.
Fig. 5 is a view taken along 5-5 of Flg. 4.
20 Fig. 6 is a view taken along 6-6 of Fig. 1~.
Flg. 7 is a view taken alon~ 7-7 of Fig. 4.
. Fig. 8 is a perspective view of another rela-
; tionship o,f hooks and spreaders on rotating disks driven
together for traversing a single strand onto the pin
~' conveyor.
'f Fig. 9 is a view taken along 9-9 of Fig. 8.
Fig. 10 is a view taken along lO-10 of Fig. 8.
Fig. ll is a view taken along ll-ll of Fig. 8. :~
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Fi~. 12 shows a typical pattern of a single~
- 30 strand restrained web havin~ parallel, dia~onal courses
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iormed by traversing the strand between the rows of strand-
restrainlng pins.
Figo 13 shows a single-strand restrained web ln
which all the courses are parallel and orthogonal to the
long direction o~ the web.
Fig. 14 shows a restrained web like the one in
Fig. 13, including details of spacing pins for achieving
- a pattexn in which ad~acent courses of the web are truly ~-
parallel. -
Fig. 15 shows a single-strand restrained web
in which the courses of the web have V-shaped re~ersals
at each side, only the alternate courses of the web being
parallel.
Fig. 16 shows a two-strand restrained web
having a patte m in which all courses are parallel and
are orthogonal to the long direction of the ~reb. ~ ~-
Fig. 17 sho~s a two-strand restrained web having `
a pattern in which all courses of the web are parallel and
are diagonal to the long direction of the web.
Fig. 18 shows a two-strand restralned web
having diagonal courses with V-shaped reversals at each
side of the web. -~
Detailed Description of the Illustrated Embodiments
Referring to Figs. l-3, a suitable framework is
indicated comprising bottom ~rame 20 and two upri~ht
frames 22, 24 moun~ed to the ~ottom frame. Positively;~
driven pr~lary disks 26 and 28 are mounted on sharts 27 `
and 29, respectively, for rotation, in the directions shown
by the arrows, in ~earlngs mounted on ~rame 22. In a
slmilar manner po~itively driven secondary disks 30, 32
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are mounted in a skewed relationship to the primary disks
on respectlve shafts 31 and 33 for rotation, in the direc-
tion of the arrows, in bearings mounted on frame 24. Posi-
tioned midway between disks 26, 28 is a dual-eyelet guide
; 34 for receiving strands 36 as they come (preferably after
passing through a tension gate~ not shown) from supply
packages 38 mounted on creel 39, which is so positioned
that the strands move freely to and through the eyelets of
the guide. The eyelets may be provided with slits to
facilitate string up.
Primary disks 26, 28 carry yarn hooks 40 attached
at five equal spacings on their peripheries and extending
outward from these disks. Each of the hooks 40 comprises
an arm with an end projecting at right angles to the arm
and there are slots formed in this end with the same spacing
-~ as the eyelets in guide 34. The plane of disk rotation is
such as to align the slots with the eyelets in guide 34.
The ælots may be formed in a number of ways, e.g.~ by groov-
ing the projecting end of the arm or by inserting pins therein.
Secondary disks 30, 32 carry spreader arms 61
attached at four equal spacings on their peripheries and ex-
tending outward from these disks. The relative speed of
rotation of the primary and secondary disks is such that hooks
and spreaders always pass by guide 34 ln the same position
relative to each other. Each spreader arm 61 has fingers
extending outward from the arm with spacings between the
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fingers that match the spacings of the eyelets in guide 34.
The path of spreader rotation is such that the fineers ~ust
clear guide 34 as they pass by. The interrelationship between
the fingers on arms 61, the slots in hooks 40, and the eyelets
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in guide 34 ~ill be described in morc detail later.
Mounted below the disks in frame 20 are a pair
of endless driven conveyors 50, 51. The conveyor 50 is
mounted on pulleyG 52, 54 and conveyor 51 is similarly
mounted on pulleys (not sho~m). Pulley 52 and its counter-
part for conveyor 51 are mounted on a~le 56 which is
mounted for rotation in bearings mounted on one end of
the frame 20, and pulley 54 and its counterpart for con-
veyor 51 are mounted on axle 57 mounted for rotation in
bearings mounted at the other end of frame 20. Both con-
veyors move together at the same rate of speed in the
direction of the arrows sho~ . Mounted on the surface of
both conveyors are upstandin~ pins 5~ for restraining the `
strands. m e pins in each row are arranged with the
spacing required to obtain the desired web pattern, and
the conveyors are moved together in such a way that the
proper relationship of pins in each conveyor with respect ~-
to the other is maintained.
Doff blades 65, 66 are rotatably mounted on
driven shaft 67 in bearings mounted on ~rame 20, These
blades are rotated in vertical planes that are close to
; but outside the paths of conveyors 50, 51. The blades
preferably have notches that match the positions of the
slots in hooks 40 as the blades rotate past the hooks.
The blades may also have notches that matcll the positions
of the spaces between fin~ers in spreader arms 61.
Synchronization of the blades 65, 66 is such that each
blade passes between an a~n 61 and conveyor 50 or 51
shortly after arm 61 passes over the conveyor. The blades
travel at a hi~her velocity t~lan the velocity o~ the arms, ~
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the blades pre~erably being given five to fi~teen rotatlons
for each rotation of primary disks 26~ 28.
Although all the various motors, pulleys, belts or
like mechanical means have not been completely illustrated
in the drawings or completely described in the specification
~or driving or supporting the various rotating disks and
conveyors in their desired or required speeds or with the
rotation indicated by the direction arrows, it is to be
appreciated that such elements and descriptions have been
omit~ed to keep the drawings and the description succinct
and to avoid the introduction o~ matters which are well known
expedients in the art. The mechanical driving means and
various ~rames which are used are conventional and merely
involve the application of well known mechanical principles.
, Referring now to Figs. 4-7, the operation of the
hooks 40, the spreader arms 61 on the rotating disks along
,~ with the endless conveyors 50, 51 and their respective
doffing blades 65, 66 provides the means for slideably en-
gaging the strands and traversing them toward one and then
the other row of pins 59 on each conveyor. A loop in each
strand is formed during each traverse and then the loop is
brought into a plane substantially parallel to the plane of
the conveyors before bein~ disengaged from the hooks and
spreaders and then deposited around pins 59 on the respective
conveyors to form an ortho~onal web 37 movlng in machine
direction L. More particularly, Fi~. 4 shows two strands
; 36 being fed from a source of supply to the eyelets of gulde
34 located above the plane of the conveyors 50, 51 and each
strand is thence led toward and beyond conveyor 51 by the
hook 40 on primary disk 28 in a traversine plane which
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contains its respectlve eyelet in euide 34 and ls transverse
to the plane of the conveyors. As the strands are led toward
conveyor 51 they are lntercepted and slideably engaged by a
hook 40a on pr~mary disk 26 at a location between conveyor
51 and guide 34 and each strand is thereupon led by a first
point of sl~ding engagement on hook 40a through an arc in the
traversing plane towards conveyor 50. As the strands are led
toward conveyor 50 the fingers of spreader arm 61a move down
between the strands and across the traversing plane of each
strand to intercept each strand in a second point of sliding
engagement. This ~ction is caused by mounting the primary -
and secondary disks so that, in the vicinity of the inter-
~ection o~ the planes o~ the two disks, the tips of the
6preader fingers are farther away from the center of the
primary disk than the hooks are. Thus, the strands are led
-` by spreader arm 61a still towards conveyor 50 but also away
from the traversin~ plane in a direction opposite the motion
of the conveyors through an arc in the skew plane of second-
ary disk 30, said skew plane intersecting both the travers-
ing plane and the conveyor plane.
While the strands are being led towards conveyor
50 after being intercepted by hook 40a and then spreader arm
61a, each strand is formed as an open loop, with one corner
o~ the loop moving ln the traversing plane and one corner mov-
lng in the skew plane. Each loop is led beyond the conveyor
50 whereupon the strands are intercepted by do~f blade 65
slideably engaged around the pins 59 of conveyor 50. To
show this clearly, locations 5-5, 6-6 and 7-7 on Fig. 4 are
presented as enlar~ed views (Figs. 5, 6, 7) of the relation-
ship o~ the strands, hook and spreader duri~g the traverse
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through those locations. Referring now to Fig. 5, eachhook 40a has an end 42 projecting at a right angle and there
are slots 43 in the end 42 with the same spacing as the
eyelet in guide 34 and each spreader arm 61a has at its
extreme end fingers 63 which extend outward from the arms
and also form spacings 64 which match the spacing of the
eyelets in guide 34. The fingers 63 have engaged strands
36 and are leading them towards the conveyor 50 but away
~rom the traversing plane. In Fig. 6, taken at location
6-6 of Fig. 4, the open loops are shown being formed and in
Fig. 7 this is shown more clearly wherein the strands 36
have been led by two sliding points of engagement, one on
each slot of the hook 40a and one on each finger of the ;~
spreader arm 61a in the form of open loops beyond the con-
veyor 50. Each loop consists o~ three sections, a side
~ection 36a between the guide 34 and the spreader arm 61a,
an end section 36b between the two sliding points of engage-
ment on the spreader arm and the hook and side section 36c
between the ho~k 40a and conveyor 51. The loop is moved to
the conveyor plane by the action o~ do~f blade 65 so that
the side sections 36a and 36c are deposited ln intervals
between pins 59 on conveyor 50, the end section 36b of the
loop bridges a designated n~nber of pins. All of the slide-
able engaging points holding both loops are disengaged from
the strands during the depositlon of the loops.
Figs. 8-11 represent an alternate embodiment
with four hooks and spreader arms placed at equal spacing
around the periphery of each pr~nary and secondary disk.
These disks as with the preferred embodlment are in a
skewed relationship with each other, however, companion
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primary and secondary disks (26' and 30~; 2~ and 32')
are driven together ~or traversine a single strand onto
the pin conveyors. Similar elements have been eiven the
same numbers only the numbers have been primed.
Conveyors 50', 51' comprising t~ro rows of strand-
restralnlng elements (i.e., pins 59'~ which are parallel to
and spaced apart from one another, defining a conveyor
plane, are moved longitudinally in the same direction in
the conveyor plane.
A strand 36' is fed from a source of supply 38'
to a forwardin~ point (guide 34') located midway between
the two rows and at a distance from the conveyor plane,
and the strand is thence led to~ards one o~ the rows
(conveyor 51') in a traversing plane which contains -the
~oruardin~ point and is transverse to the conveyor plane,
intercepting both conveyors.
As the strand is led towards one of the rows
(conveyor 51'), it is intercepted and slideably engaged -
: by hook 40a' between that row and the guide 34 ', and the ;
strand is thereupon led by a first slidin~ point of
engagement on hook 40_' throu~h an arc in the traversin~
. . .
plane towards the other row (conveyor 50', Fig. 8).
As tlle strand is led toward conveyor 50' it is
intercepted a~ain between the rorwarding point (guide 341 )
and the first slic~ine point o~ en~agement on hook 40a' by
spreader 61a' (Fig. 9) and is then led by a second sliding
point Or en~a~ement on spreader 61a', still towards the other
row but also away from the traversing plane in a direction
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opposite the direction o~ motion of the con~eyors 50', 51',
through an ~rc in a slcew plane, sald skew plane intersectine
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both the traversine plane and the conveyor plane (Fig. 10).
While the strand is being led towards the other
row (conveyor 50') after the two interceptions, it is
being held in an open loop ~hairpin loop) having three
sections: a side section 36a' between the fo~qarding
point and the second sliding point o~ engagement, an end
section 36b' between the two sliding points of engage-
ment, and a side section 36c' between the hoolc 40a' and
conveyor 51'.
The strand is led by the two sliding points of
engagment in the form of the open loop beyond the other row
o~ strand-restrainlng elements, whereupon the strand is
intercepted by doffing blade 65~ (~ig. 11) and slideably
engaged upon each side section of the loop at points near
the conveyor and moved to the conveyor plane, so that the
side sections of the loop are depo~ited within intervals be-
tween the strand-restraining elements~ the end section of
the loop bridging a designated n~nber of intervals between
strand-restraining elements. All o~ the slideable engaging
points are disengaged from the strand during the deposition
of the loop.
Fig. 12 illustrates a typi~al web pattern o~-
tained by traversing a single strand 36' around the pins
59' in the manner sho~m in Fig. 8, the completed web mov- ` -
ing in the lon~ or machine direction of the web as sho~m
by the arrow L parallel to the center line o~ each row of
.. . .
pins. The completed web is restrained by the pins, whicl
hold pin~contactin~ se~ments of the strand. ~s shown in
more detail in Fi~. 14, the pin contactlng segments 104
are defined ~y t~ngent points 105 at the outermost point ~-
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of each pin, and 106, on or near the center line of the
row of pins. In addition to the pin-contacting segments,
the web comprises courses 107 lying between tangent points
106 at opposite sides of the conveyor and selvage segments
108 parallel to web direction L lying outside the rows of
pins between tangent poin~s 105. With respect to the cross
direction C of the web, normal to L, and with respect to
the forward direction of the web, adjacent courses are laid
down at angles aL and aR from the left and right sidés
of the conveyor (Fig. 12), respecti~ely. The effective
strand directlon during the strand laydown is shown by
arrow SL for angle aL and by arrow SR for angle aR. In
the pattern specifically shown in Fig. 12, each course
is laid do~ parallel to the previously laid do~m course,
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æo that aL = ~aR- The loop fo~ned in the strand during
each traverse as the web is laid down is sufficiently
wide to be deposited around two pins at each side of the
conveyor, the end of the loop on the supply side of the
strand being one end of the next course to be laid down.
Fig. 13 represents the special situation in
which aL = aR = - Each course o~ the web is orthogonal
to the long direction of the web, the strand ~eing laid
down at right angles to the direction of the motion of
the conveyor. All courses are parallel to one another.
In order for each course o~ the web to be truly
parallel to the precedin~ course, as in the web patterns
of Figs. 12 and 13, each end of each course (tan~ent
point 10~) must ~e equally spaced in the lon~ direction
of the web from each end of ~he precedin~ course. ~ first
30 requixement ~or achievin~ such parallellsm is ~ pin
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arrangement in which the pins on each slde o~ the con~
veyor nre arranged in identlcal spaclng patterns, the
pins in each row bein~ positioned for equal spacing of
the tan~ent points 106 at which the courses contact the
pins (rather than equal center-to-center spacing of the
pins). Fig. 14 shows a suitable pin arrangement for
obtaining the web laydown pattern shown in Fig. 13. Each
row of pins comprises pairs of pins of diameter d having
centers spaced apart by distance D, the center of each
10 pin in each of such pairs being separated in the direc-
tion away from the other by a distance D ~ 2d from the
center of the nearest pin of the next pair in the same
row. The ends 106 o~ adjacent courses are thereby
equally spaced from one another on each side in the long
direction of the web, the spacing being the distance
D ~ d in the arrangement shoun in Fig. 14. The patterns
of the two rows are offset with respect to one another
such that each pair of pins (separated by center-to-
center pin spacing of D) is positioned opposite a gap
having a center-to-center pin spacin~ of D ~ 2d on the
other side, ~hich positions the courses ortho~onal to the
long direction of the web. For diagonal laydown Or
patterns with true parallelism o~ ad~acent courses~ such
as shown in Fig. 12, the appropriate positionin~ o~ pairs
of pins on one side of the conveyor with respcct to the
pairs of pins on the other side is the same as the posi~
tionin~ employed for the correspondin~ ortho~onal pattern,
except that the pairs of pins on the right side are orfset
b~ an~le aL from the correspondin~ gap on the other side.
3o In the precedln~ discussion the strnnd dlameter has been
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treated as ne~ligible. For more precise parallellsm,
and especially ~hen the strand di~neter ls not negligi-
ble, the pin spacing should be arranged for equal spacing
of the center points of the strands in adJacent courses.
In addition to pin spacing, factors controlling
the laydown pattern for each strand include the direc-
tions in which the strand is traversed from left to right
and rrom right to left, the direction of loop formation
with respect to the direction of web laydown, and the
10 speed of the conveyor with respect to the rate of strand i~
deposition along thé selvage. In setting up the apparatus
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to lay down a ~reb pattern in which aL = -~R (including
aL = aR = ), the primary hooks are pre~erably mounted ~-
to rotate in the same plane on each side of the guide.
During each traverse o~ the strand a loop is
~ormed which can be readily deposited around the strand- -
restrainin~ elements, e.g., a pin or pins. m e loop needs
to be of sufficient width to span the targeted pins or
other strand-restraining elements in their entirety so
that deposition can be completed e~ectively, but should
be only slightly wider than the maximum distance to be
spanned; othe~ise, strand deposition is Jerky because
the loop collapses under tension until it is restrained
The normal manner ~or ~orming loops is to ~onn them in the
direction away from the direction in which the completed
web is moving, i,e , in the direction away ~rom the co~lrse
which has just been laid down. Formin~ the loops in this
normal manner is a second requirement for lnyinlr down each
course o~ the we~ truly parallel to the precedin3 course.
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` 30 The conveyor carryin~ the rows o~ pins can ~e
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ad~usted to opcr~te at any desired speed. The rate of
travel of the pins is thus independent of the rate at
which loops are generated and laid do~ to form selvage
segments. Accordingly, a third requirement for laying
; down each course truly parallel to the preceding course
is ~hat the distance traveled by the conveyor per unit
of time be set equal to the total distance between
courses of a single strand laid down per unit of time.
In forming the patte m of Fig. 15, the pins are
equally spaced along each row in staggered relationship
to the pins on the opposite side of the conveyor. The
strand is laid down during each traverse at an angle to
L, in the direction ~way from the course ~hich has just
been laid do~, but during each traverse only a small loop
ls formed, the size of the loop bein~ suita~le Lor de-
position about a single pin. The conveyor is operated at
a speed sufficient that adjacent courses are laid doT~ at
the desired angles aL = aR f negative sign. In this lay-
do~. pattern the strand thus makes essentially a V-shaped
re~ersal, the pin-contactin~ segments of the s~rand oeing
in contact with a~nost half the circumference of each
pin. This web pattern contains no selva~e section OL the
strand parallel to the rows of pins between courses.
Fig. 16 illustrates the web pattern obtained
by traversing two strands, 108 (solid line) and 109 (line
; ~
of dashes), in the manner sho~n in Fig. 4. To show the
paths of each of the strands alons the selva~e more
clearly, one of the strands is shown spaced nway from the
pins, although both of the strands are actually in contact
~; 3 with the p~ns around which they are traversed, In the
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restrained web so obtained, all courses are orthogonal
to the long direction of the web. The loops formed during
traverse span three pins (more generally, n + 1 pins are
spanned by each loop when n strands are traversed). For
each strand the pins are spaced in a manner analogous to
that shown in Fig. 14 (using a relatively large value for
D), the pins for the other strand being inserted in each
row in positions providing equal distances between the ~-
courses in the web. In this pattern ~L ~ ~R =
Fig. 17 illustrates the web pattern obtained by ;
traversing two strands 111, 112 in a manner analogous to
that employed in Fig. 12 for a single strand. In -the
restrained web so obtained all courses are parallel to one
another in the same diagonal direction between the two rows
of pins. The loops formed during each traverse span three -
pins, only the first pin and the third pin being utilized
for restraining any given strand. In this pattern ~L =
~R-
Fig. 18 illustrates the web pattern obtained by
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traversing two strands (108' and 109') in a manner analo-
gous to that employed in Fig. 15 for a single strand. Dur-
ing each traverse of each strand a small loop is formed and
deposited around a single pin. The two strands are traversed
together, each being deposited at the end of each traverse
around the second pin in the row from the las-t pin on the
~7 same side restraining the same strand. The web is charac-
; terized in appearance as an array of diamond-shaped patterns.
In this pattern aL ~ ~R (both of negative sign).
Webs formed by the method and apparatus of this
invention may be employed for any of the purposes described
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in the prior art for cross-laid webs.
In the apparatus oE the invention the operations
of traversing and depositing the strands are advantage- -
ously carried out with mechanical components which move
in simple rotary pa-ths. Web formation at strand feed speeds
in excess of 1000 yards per minute is readily obtained.
Although four hooks and four spreaders are shown
on the disks of Fig. 8 and five hooks and four spreaders
on the disks of Fig. 4 other combinations of hooks and
spreaders are possible. When more than one strand is tra-
versed, it is preferred to have fewer spreaders than hooks.
It is also preferred to engage the strand with a hook on ;~
one side prior to deposition of a loop on the other side of
the eonveyor.
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